1. Field of the Invention
The invention relates to rotary saws provided with a self leveling protective saw blade guard particularly for rotary masonry saws and the like pivotally mounted on a support frame and an adjustable spring biased positioning mechanism manually operable for initially positioning and rocking the saw blade into and out of cutting engagement with a workpiece.
2. Description of the Prior Art
The prior art discloses rotary saws with various mechanisms similar in some respects for the purpose of initially positioning and rocking the saw blade and maintaining, at all times, the lower edge of the saw blade guard in a horizontal or level position and out of engagement with the workpiece regardless of the amount of relative pivotal movement.
Examples of saw blade positioning and self leveling guard mechanisms of which the applicant is aware are disclosed in the following U.S. Pat. Nos. 3,834,369; 2,998,813; 2,972,344 and 2,320,743 and in a rotary saw manufactured by Robert C. Evans Co. of Kansas City, Mo. and sold under their trademark TARGET GUARD/MATIC. Each of the mechanisms disclosed in the prior art attain the same objective but in a manner which distinguishes in one or more respects from one another and the applicant's mechanisms disclosed hereinafter.
The applicant's masonry saw distinguishes from the known prior art cited above in that the self leveling guard has followers fixed thereon which are adapted to project into, move in, and be retained in arcuate channels between engaging arcuate guide surfaces on a guide member fixed to and pivotable with the platform.
Also, the applicant's saw blade positioning and pivoting means differs in that an adjustable tripivot lever pivotally linked to an adjusting screw and the platform, is pivotally mounted on, movable with and adjustable relative to a short lever arm of a foot lever pivotally mounted on the frame.